Hexagonal PtBi Intermetallic Inlaid with Sub-Monolayer Pb Oxyhydroxide Boosts Methanol Oxidation

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Developing multicomponent nanocatalysts is crucial for advancing electrocatalysis.
• Precisely engineering multimetallic active sites at the atomic level remains a significant challenge.

Purpose of the Study:

• To report a novel nanoengineering strategy for constructing well-defined multimetallic active sites.
• To enhance the electrocatalytic activity for the methanol oxidation reaction (MOR).

Main Methods:

• Surface inlay of sub-monolayer lead (Pb) oxyhydroxide onto hexagonal platinum-bismuth (PtBi) intermetallic nanoplates.
• Utilizing Density Functional Theory (DFT) calculations to understand reaction mechanisms.

Main Results:

• The PtBi@6.7%Pb nanocatalyst showed 4.0 and 7.4 times higher mass activity than PtBi nanoplates and commercial Pt/C for MOR in alkaline electrolyte.
• Achieved a record mass activity of 51.07 A mg^-1 _Pt at 60 °C in direct methanol fuel cells.
• DFT revealed Pb oxyhydroxide promotes electron transfer, suppresses CO poisoning, and optimizes electroactivity through p-d coupling.

Conclusions:

• The developed PtBi@6.7%Pb nanocatalyst offers superior performance for the methanol oxidation reaction.
• This nanoengineering approach provides a viable strategy for designing advanced multimetallic nanocatalysts.
• The findings contribute to improving electrocatalysis for fuel cell applications.